Using the traditional glassblowing technique called lampwork, each glass button is made of borosilicate glass, also known as Pyrex. The glass is formed by hand with a torch and then annealed, reinforcing the glass button to near unbreakable durability. Annealing is a strengthening process of slowly cooling glass to relieve internal stresses by using a kiln. Buttons that are made with shanks are reinforced with a glass shank that is hot welded on.
